Hydrofluorination of Alkenes Using Et₃N·HF under Dual Cobalt and Photoredox Catalysis

Key words

alkenes - cobalt catalysis - hydrofluorination - photoredox catalysis

Significance

A dual cobalt- and photoredox-catalyzed method for the regioselective hydrofluorination of alkenes using Et₃N·HF as HF surrogate is reported. This protocol features a broad substrate scope, tolerating both unactivated aliphatic alkenes and styrenes. Exploiting the structure–activity relationships between the structurally modular cobalt(II) salen complexes and different alkene classes through high-throughput experimentation provided access to a range of hydrofluorinated compounds with varying substitution patterns.

Comment

This methodology was also applicable to the ¹⁸F-labeling of diverse biologically active compounds. Mechanistic experimental investigations including Stern–Volmer and voltammetry studies along with DFT calculations support the shown catalytic cycles. However, distinctive pathways could be identified in the nucleophilic step of this polar-radical-polar crossover mechanism depending on the alkene structure. Ongoing studies aim to deepen the understanding of this process.

Publikationsverlauf

Artikel online veröffentlicht:
15. April 2024